Fix GatewayProxyInitAotProcessor for proper type

The `GatewayProxyInitializationAotProcessor` uses mistakenly a `ProxyFactoryBean` type
instead of an expected `GatewayProxyFactoryBean`.
Looks like we don't need to scan for interfaces since they are properly transformed
to the `AnnotationGatewayProxyFactoryBean` bean definition during AOT phase

Author: artembilan

spring-integration-core/src/main/java/org/springframework/integration/aot/GatewayProxyInitializationAotProcessor.java

@@ -17,17 +17,14 @@
 package org.springframework.integration.aot;
 
 import java.util.Arrays;
-import java.util.List;
 import java.util.stream.Stream;
 
 import org.springframework.aop.framework.AopProxyUtils;
-import org.springframework.aop.framework.ProxyFactoryBean;
 import org.springframework.aot.hint.ProxyHints;
 import org.springframework.beans.factory.aot.BeanFactoryInitializationAotContribution;
 import org.springframework.beans.factory.aot.BeanFactoryInitializationAotProcessor;
 import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
 import org.springframework.beans.factory.support.RegisteredBean;
-import org.springframework.core.annotation.AnnotatedElementUtils;
 import org.springframework.integration.annotation.MessagingGateway;
 import org.springframework.integration.gateway.GatewayProxyFactoryBean;
 import org.springframework.integration.gateway.RequestReplyExchanger;
@@ -45,22 +42,11 @@ class GatewayProxyInitializationAotProcessor implements BeanFactoryInitializatio
 
 	@Override
 	public BeanFactoryInitializationAotContribution processAheadOfTime(ConfigurableListableBeanFactory beanFactory) {
-		List<RegisteredBean> registeredBeans =
+		Stream<? extends Class<?>> gatewayProxyInterfaces =
 				Arrays.stream(beanFactory.getBeanDefinitionNames())
 						.map((beanName) -> RegisteredBean.of(beanFactory, beanName))
-						.toList();
-
-		Stream<Class<?>> gatewayProxyInterfaces =
-				Stream.concat(
-						registeredBeans.stream()
-								.filter(bean -> ProxyFactoryBean.class.isAssignableFrom(bean.getBeanClass()))
-								.map((bean) ->
-										bean.getBeanType().getGeneric(0).resolve(RequestReplyExchanger.class)),
-						registeredBeans.stream()
-								.map(RegisteredBean::getBeanClass)
-								.filter(beanClass ->
-										beanClass.isInterface() &&
-												AnnotatedElementUtils.hasAnnotation(beanClass, MessagingGateway.class)));
+						.filter((bean) -> GatewayProxyFactoryBean.class.isAssignableFrom(bean.getBeanClass()))
+						.flatMap((bean) -> Stream.ofNullable(bean.getBeanType().getGeneric(0).resolve()));
 
 		return (generationContext, beanFactoryInitializationCode) -> {
 			ProxyHints proxyHints = generationContext.getRuntimeHints().proxies();